As hardware for reproducing and storing high resolution or high quality video content is being developed and supplied, a need for a video codec for effectively encoding or decoding the high resolution or high quality video content is increasing. According to a conventional video codec, a video is encoded according to a limited encoding method based on a macroblock having a predetermined size.
Image data of a spatial region is transformed into coefficients of a frequency region via frequency transformation. According to a video codec, an image is split into blocks having a predetermined size, discrete cosine transformation (DCT) is performed for each respective block, and frequency coefficients are encoded in block units, for rapid calculation for frequency transformation. Compared with image data of a spatial region, coefficients of a frequency region are easily compressed. In particular, since an image pixel value of a spatial region is expressed according to a prediction error via inter prediction or intra prediction of a video codec, when frequency transformation is performed on the prediction error, a large amount of data may be transformed to 0. According to a video codec, an amount of data may be reduced by replacing data that is consecutively and repeatedly generated with small-sized data.
According to a multi-layer video codec, a base layer video and one or more enhancement layer videos are encoded and decoded. By removing temporal or spatial redundancy between the base layer video and the enhancement layer videos and redundancy between layers, an amount of data of the base layer video and the enhancement layer videos can be reduced.